Method for processing information parts of recorded data

ABSTRACT

The method, device and medium according to the invention provide (restricted) forward compatibility to higher device/medium versions. It is provided a defined behaviour of an older device, if it has to handle information of a higher version number than supported by itself. A device according to the invention is able to provide restricted (e.g. playback) functionality of its records to older devices. So, a newer device is assured, that older devices will not damage the additionally stored information: This is important, because only a newer device is able to understand these additional information, and to process it correctly.

The invention relates to a method for processing information parts ofrecorded data, a respective processing device and a respective recordingmedium. There exist several media on which data to be processed can berecorded, e.g. magnetic tapes or disks, optical tapes or disks, solidstate memories etc. For each of such recording media, several standardson how to record and how to organize the data exists.

In case of a new standard for processing, e.g. recording, data, or incase of a new upgraded version of such standards, records of recordingdevices working according to that new standard or version are notreadable by recording devices of an older version.

According to some standards version numbers are used to indicate theversion of its assigned recorded information. If a device detectsinformation indexed by a higher version number than the version numbersupported by the device itself, then this device will reject thisinformation, because the device does not know anything about thestructure of this information. This has the effect that the device isnot able to access to the information and will stop any furtherprocessing of the information.

However, it is important to take care of future versions of a standard.If there is taken no care of later versions, then the behaviour of theolder devices may be arbitrary in the case of handling version updatedinformation. Arbitrary behaviour of older devices, or such non-existenceof forward compatibility is a big disadvantage.

It is an object of the invention to provide forward compatibility.

This object is solved by the method as described in claim 1.

Recorded data consists of one or several information parts, which may berelated to each other. This means that processing of the recorded datain general requires different information parts to be processed, whichinformation parts may refer to each other. Each information part may bechanged in order to change or amend the recorded data without changingthe other information parts. In case two information parts refer to eachother, changing of one of them may necessitate a change of the other inorder not to destroy consistency. The rules given by a certain versionof a standard take care of such necessities. Processing types are forexample generating process, read process, append process, i.e. to addsomething at a predefined location of the information part, preferablyat its end, or edit process, i.e. to change the content of theinformation part. According to the invention an information part isprocessed at least by some of the available processing types, even ifthe available processing types comply to an earlier version of thestandard than the information parts. This has the advantage of forwardcompatibility of an older device for at least some processing typesbeing in conformity with a newer version of a standard. Even an olddevice can read information parts, which were created by a new device incompliance with a later version of the standard than the version towhich the old device complies. However, it is prevented that the olddevice destroys information that complies to the later version of thestandard by not permitting the old device to perform append or editprocessing types.

Preferably processing is done according to a version of the standardhaving a lower version number than the processing version number in casethat the information part version number is lower than the processingversion number. This assures correct interpretation of the informationcontained in the processed information part as intended according to theold version of the standard to which the information part complies.Preferably, processing is performed according to the version of thestandard identical to the information part version number. However,processing according to a version number higher than that but not higherthan the processing version number is done as long as correctinterpretation is assured.

Preferably, processing is permitted as long as the processing versionnumber and the information part version number do not differ from eachother about more than a predefined value. This assures limited forwardcontrol. In case that a future version of this standard cannot bedesigned such to guarantee compliance of a certain information part withprevious versions even for those processing types for which this waspossible for previous versions, then the version number of this newversion of the standard is chosen such that the difference exceeds saidpredefined value. This allows, for example, read processing for anyversion of the standard while append processing might be permitted onlyfor versions n.xx and n+1.xx for a device being in compliance withversion n.00. A new version of the standard that would not guaranteecompliance for the append process with older devices would, therefore,require a version number n+2.xx.

According to the invention a processed information part is provided witha new information part version number, which indicates the lowestversion of the standard to which the processed information part compliesbefore said processed information part is transmitted. This assurescorrect further processing of the processed information part, even ifprevious processing has changed some characteristics, and even if thesechanges are not in conformity with the version of the standard theinformation part previously was in conformity with. In general this willcause an increase of the information part version number. However, theremay also be a decrease of the information part version number in casethat during processing, such characteristic have been removed, whichmade necessary compliance to a higher version of the standard.Transmission is, in this meaning, for example a transmission within thesame device or to another device, by wire or wireless. The informationpart is transmitted for example to be displayed, to be recorded, to befurther processed or to be handled in another appropriate way.

Preferably, several information part version numbers are attached to asingle information part. This has the advantage that for severalprocessing types different version numbers can be assigned thusincreasing flexibility of compatibility design.

A reading and/or recording device for performing the method as describedabove is also part of this invention.

A recording medium according to the invention comprises informationparts, which are generated according to the inventive method or asimilar method. Such recording medium comprises information parts thatbelong to one set of recorded data, these information parts havingdifferent information part version numbers although they are related toeach other to form, in combination, the recorded data.

The invention is described below in some specific examples, more detailscan be seen therefrom. However, also other combinations of features arecovered by the invention.

In the figures

FIG. 1 shows a flowchart of an inventive method,

FIG. 2 shows a recording medium according to the invention.

The rectangle “derive lowest version number” is described by FIG. 3.

FIG. 3 shows a flowchart of deriving the version number for eachinformation part. This procedure describes the rectangle “derive lowestversion number” of FIG. 2. In this flowchart “vn” means version numberand “ip” means information part.

In the following there is described a definition of a version number,which provides restricted forward compatibility of a device to laterversions. This is performed by a special definition of the meaning ofthe version number. This special definition contains restrictions forlater versions. So, the behaviour of later versions follows some rules.These rules guarantee the structure of information covered byinformation containers, e.g. descriptors, of later versions of astandard.

An information part, e.g. a separated file, shall contain an informationpart version number inv. This information part version number invindicates the version of the encoder, which generated this informationpart. It is to be noted, that the encoding device may be even of ahigher version number than this generated version number inv. It is alsopossible that one device generates different version numbers inv1, inv2,. . . for different information parts ip1, ip2, . . .

If another device shall process such information parts, ip1, ip2, . . .then it has a look for the respective information part version numbersinv1, inv2 . . . . If the version number inv of such an information partis equal or lower than the processing version number rnv supported bythe device itself, then full support of all features is provided by thedevice.

If the version number inv of such an information part ip is higher thanthe processing version number rnv supported by the device itself, thenthe device does support only restricted access to the information partip and assigned data and information. This restricted access means, thatthe access is for example restricted to only read processing, e.g.playback, for the information part and its assigned data or to readprocessing and restricted write processing, e.g. append new informationand data, of the information part and its assigned data. Restrictedwrite processing means, that a change of the information part orassigned data and information are permitted to be changed in arestricted manner, e.g. to append new data or information, but prohibita change of already recorded information and data.

In order to support more flexible forward compatibility preferably morethan one version number indicator is provided for the same informationpart ip. For example:

A first version number inv defines the readability, e.g. for playback,of the information part ip for devices of later versions, and

a second version number inv of the same information part ip defines therestricted write access for edit processing, e.g. cut and changeinformation and data, and

a third version number inv of the same information part ip defines therestricted write access for appending new information and data to theinformation part ip and its assigned information and data, and

a fourth version number indicates the actual version number of the usedencoder for generating the information part. This is useful especiallyfor devices of higher version rnv. They use such information for exampleto automatically correct, or provide workaround(s) for, known bug(s) ofthis specification or known device bug(s).

The following table describes the behaviour: record device append editversion number (e.g. add a (change (rnv) in comparison new already tothe version read recording, recorded number of the (e.g. leave the oldrecords, e.g. information part play- records delete a (inv) back)unchanged) record) rnv < inv −> old yes yes/no (3) no (4) device (1) rnv= inv yes yes yes rnv > inv −> new yes yes yes (2) device (2)

The indication “yes” means that the respective processing type ispermitted, “no” means that it is not permitted. Some limitations areindicated by (1) to (4), having the following meaning:

(1) But, only the features of the old version will be supported.

(2) The new device has to support the old version of the standard. Thisis necessary, because even a newer device has to be aware of the oldversion to be able to interpret the stored information as intended bythe old version.

(3) This feature may be supported (“yes”) or not (“no”) This depends onthe level of version number difference and how strong the structuredifferences between the processing version number rnv of the device andthe information part version number inv are.

(4) A change of the information part cannot be supported, because theold device does not know anything about the additional informationsupported by the new version of standard. A change of the informationcould lead to inconsistencies inside a certain part of the informationpart ip, which certain part is only supported by a new device.Therefore, for an old device it is strongly forbidden to change alreadystored information generated by a newer version of a standard.

FIG. 1 shows a flowchart on how to decide which processing types are tobe available for a certain information part ip.

If the actual version of the standard defines more than one informationpart as part of the complete information set, then a device shall,according to the invention, store each information part ip with an aslow as useful information part version number in order to provide asmuch as possible functionality and access to older devices. For example,if a higher version information part number for one information part isnecessary to provide voice annotations, but no voice annotations weremade for this record, then the information part is stored using theformat defined by the old version of the standard.

An example about how information part version numbers inv may changeduring processing is described as follows:

A device supports exact 4 information parts ip1, ip2, ip3 and ip4, eachwith an information part version number inv1, inv2, inv3, inv4. Thedevice supports the processing version number rnv=3.0 and all previousprocessing version numbers 1.0, 1.1, 1.2, 2.0.

The history of ip1: launched with version number 1.0, slightly changedfor 1.1, not changed to 1.2, slightly changed to 2.0, not changed to3.0.

The history of ip2: launched with version number 1.0, not changed untilinclusively 3.0.

The history of ip3: launched with version number 2.0, expanded tosupport optional additional information (only voice annotations areadded to this version of the standard) slightly changed for versionnumber 3.0.

The history of ip4: launched with version number 3.0. It contains linksto the content of ip1. A change of ip1 content requires a change of ip4information. The recording of ip4 is optional. It shall be recorded forthe case that additional metadata about the record has been received(during the recording).

Example Scenario Number 1:

The record device (of version 3.0) makes a record. No voice annotationsare done and no additional metadata are received.

The used version numbers are described by the used version numbers ofthe 4 information parts:

ip1: 2.0, because, there is no difference between ip1 of version 3.0 andip1 of version 3.0, and no ip4 is recorded.

ip2: 1.0, because ip2 of version 1.0 and 3.0 are the same and there isno version dependent relation to other information parts.

ip3: 2.0, because no voice annotations are done, therefore version 3.0for ip3 is not necessary

ip4: not recorded, because additional metadata were not recorded.

Example Scenario Number 2:

Start point: Result of scenario 1 (the previous scenario). Now, the userperforms (offline) a voice annotation. The used version numbers aredescribed by the used version numbers of the 4 information parts:

ip1: 2.0 no need for a change.

ip2: 1.0, no need for a change.

ip3: 3.0, because only this version supports voice annotations.

ip4: not recorded, because additional metadata were not recorded.

Example Scenario Number 3:

Start point: Result of scenario 2 (the previous scenario). Now, the userreceives additional metadata for its records (e.g. via internet). Theused version numbers are described by the used version numbers of the 4information parts:

ip1: 3.0 Now, ip4 was recorded: A change of ip1 would lead toinconsistencies related to the content of ip4. Therefore, only a deviceof version 3.0 would be able to perform a change of ip1 as necessary tokeep the consistency of all information parts.

ip2: 1.0, no need for a change.

ip3: 3.0, no need for a change.

ip4: 3.0, because this is the place for the additional metadata. Becausethe (new) existence of this information part, ip1 must be of version 3.0to indicate that an older device shall not edit (e.g. cut or delete)data inside ip1, because this could lead to inconsistencies between ip1and ip4.

After the third scenario, a device of e.g. version 2.0 would be able touse ip1, ip2 and ip3 for playback and would be able to append newrecords and this device would be able to edit ip2 because ip2 is stillmarked as version 1.0. But, it is not allowed for the device to editip1, ip2 or even ip4. Of course, the existence of ip4 is not known by adevice of version 2.0.

Example Scenario Number 4:

Start point: Result of scenario 3 (the previous scenario). Now, the userremoves ip4. The used version numbers are described by the used versionnumbers of the remaining 3 information parts:

ip1: 1.0 (now, ip4 was removed: A change of only ip1 wouldn't leadanymore to any inconsistencies between the remaining information parts.Therefore, a version 1.0 device may perform a change of ip1 if desired).

ip2: 1.0, (no need for a change).

ip3: 3.0, (no need for a change).

ip4: was removed

It is recommended to assign automatically the highest version numberused by any of the stored information parts for the recorded data, e.g.streams, which shall be controlled by the information parts. That means,that an older device will not edit the recorded data. That keeps theconsistency of the recorded data with the (newer) information parts. Itis strongly recommended to implement this rule as part of thespecification.

In the case of recording, the following restriction for generating theversion numbers should apply:

A format version (described by the version number) shall be used whichcovers all required properties (e.g. features) for this information partand

the version number of the information part shall be as low as possible(in order to provide as much compatibility to older devices as possible)and

in the case of related information parts exist the version number shallbe chosen in a way (high enough), that the version number requires anediting device, which exactly knows about the complete dependencies tothe related information parts (in order to avoid inconsistencies between(however) linked information parts after editing of the information partby an older device).

The method, device and medium according to the invention provide(restricted) forward compatibility to higher device/medium versions. Itis provided a defined behaviour of an older device, if it has to handleinformation of a higher version number than supported by itself. Adevice according to the invention is able to provide restricted (e.g.playback) functionality of its records to older devices. So, a newerdevice is assured, that older devices will not damage the additionallystored information: This is important, because only a newer device isable to understand these additional information, and to process itcorrectly.

The inventive concept is useable for nearly any kind of (future)technical specification or standard. This invention describes adefinition of a version number, which provides restricted forwardcompatibility of a device to later versions. This is performed by aspecial definition of the meaning of the version number. This specialdefinition contains restrictions for later version. So, the behaviour oflater version follows some rules. These rules guarantee the structure ofinformation covered by information containers (e.g. descriptors) oflater specification versions. Of course, these rules should be definedin all versions of the same standard. If there is one version accordingto which these rules are not required, it is probably not possible toguarantee forward compatibility for this version and all previousversions.

1) Method for processing information parts of recorded data wherein eachinformation part is provided with an information part version number,said information part version number indicating the version of astandard to which the information part complies, each information partmay have a different version number, and processing being performed incompliance with a version of said standard being indicated by aprocessing version number, for processing different processing typesbeing available, the method comprising the steps of reading theinformation part version number of an information part, comparing theread information part version number with the processing version number,if the read information part version number is lower than or equal tothe processing version number permitting every processing type to beperformed, else permitting only some processing types to be performed,processing the information part using said allowed processing types. 2)Method according to claim 1, wherein performing processing for at leastone information part according to a version of the standard having alower version number than the processing version number if the readinformation part version number is lower than the processing versionnumber. 3) Method according to claim 1, wherein permitting a processingtype to be performed in case the information part version number and theprocessing version number being different but this difference notexceeding a predefined value. 4) Method according to claim 1, wherein,after processing, providing a processed information part with a newinformation part version number, said information part version numberindicating the lowest version of the standard to which the processedinformation part complies, transmitting said processed information part.5) Method according to claim 1, wherein providing different kinds ofinformation part version numbers to a single information part fordifferent kinds of processing types. 6) Reading and/or recording devicefor performing the method of claim
 1. 7) Recording medium comprisinginformation parts being generated according to the method of claim
 1. 8)A recording medium comprising information parts being generated by thedevice according to claim 6.